Crane with means for removing worn lines

ABSTRACT

A trolley, movable along a boom that extends laterally away from a supporting tower, carries anchor drums and vertical sheaves and releasable means normally locking the drums against rotation. Lines wound on supply reels supported by the tower extend out to the anchor drums and around them and then down around sheaves connected with a load carrier below the trolley. From there the lines extend up and over the trolley sheaves and then to power drums at the tower. The lines normally are prevented from unreeling from the supply reels by releasable means, but by releasing all of said releasable means the power drums can withdraw lines from the supply reels to replace with new line the used lengths of line between the anchor drums and the power drums.

United States Patent [191 Lofink Sept. 10, 1974 1 CRANE WITH MEANS FOR REMOVING WORN LINES [75] Inventor: Gerard V. Lofink, Coraopolis, Pa.

[73] Assignee: Heyl Patterson, Inc., Pittsburgh, Pa.

[22] Filed: Mar. 21, 1973 [21] Appl. No.: 343,373

Primary Examiner-James B. Marbert Assistant Examiner-James L. Rowland Attorney, Agent, or Firm-Brown, Murray, Flick & Peckham 5 7] ABSTRACT A trolley, movable along a boom that extends laterally away from a supporting tower, carries anchor drums and vertical sheaves and releasable means normally locking the drums against rotation. Lines wound on supply reels supported by the tower extend out to the anchor drums and around them and then down around sheaves connected with a load carrier below the trolley. From there the lines extend up and over the trolley sheaves and then to power drums at the tower. The lines normally are prevented from unreeling from the supply reels by releasable means, but by releasing all of said releasable means the power drums can withdraw lines from the supply reels to replace with new line the used lengths of line between the anchor drums and the power drums.

4 Claims, 2 Drawing Figures v p gmmsm man sum 1 or 2 CRANE WITH MEANS FOR REMOVING WORN LINES This invention is concerned with cranes for lifting loads, and more particularly with clamshell bucket cranes used in unloading barges and the like. In such cranes the bucket is raised and lowered by a wire rope or line connected with a trolley on a boom and with a power drum mounted on the boomsupporting tower. The opening and closing of the bucket is controlled by another line connected to another power drum at the tower. Over a period of time these lines become worn and unsafe and therefore have to be replaced. In the past this required the lines to be removed and discarded and then replaced by new lines thathad to be restrung, which required a considerable amount of time and labor.

It is among the objects of this invention to provide a crane provided with one or more lines that can be replaced with very little effort by simply operating the power drums to pull new lengths of lines to the drums.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which FIG. 1 is a side view; and

FIG. 2 is a diagrammatid perspective view showing how the various flexible lines are strung and operated.

Referring to FIG. 1 of the drawings, a long boom 1 extends substantially horizontally away from one side of the upper portion of a structural steel tower 2. A trolley 3 is provided with wheels 4 that run on parallel rails 5 in the bottom of the boom so that the trolley can move back and forth along the boom. Rotatably mounted side by side inside the trolley is a pair of vertical sheaves 7 and 8, in front of which a pair of anchor drums 9 and 10 also are rotatably mounted, all as shown in FIG. 2. A pair of electrically driven power drums 11 and 12 are rotatably mounted on the tower. One end of a wire rope 13 or line is detachably connected to drum 11, from which the rope extends out to the trolley and then down around sheave 7 to a vertical sheave 14 (FIG. 1) journalled in the upper part of a load carrier, such as a clamshell bucket 15. The rope extends around this sheave and back up to trolley or anchor drum 9 that normally is prevented from turning by releasable means, such as a pin 16 extending through the side of the trolley and into the end of the drum. The rope is wrapped around this drum a sufficient number of times to prevent the rope from slipping and then it extends in along the boom and up to a supply reel 17 that carries a considerable length of rope. This reel is rotatably supported'on the tower. The rope normally is prevented from unreeling from the supply reel, either by locking the reel or by clamping the rope to the towernear the reel by means of a clamp 18. Instead of locking the trolley drum against rotation, the line could be clamped to the trolley near the drum.

When the load carrier is a clamshell bucket as shown, it carries another sheave 20, around which a second line or wire rope 21 extends for closing the bucket. From this sheave one length of the rope extends up and over the other trolley sheave 8 and then inwardly along like that shown in connection with the first anchor drum. From anchor drum 10 the rope extends in toward the tower and up to a supply reel 22 where it is retained either by locking the reel or by clamping the rope against the tower at 23. Since both ropes have portions between the bucket and the trolley that. are anchored at their upper ends to the drums carried by the trolley, the bucket can be raised and lowered and opened and closed by operating the power drums on the tower.

In order to move the trolley toward the tower while keeping all of the lines taut, an auxiliary trolley 25 runs on a track 26 extending from the inner end of the boom across the tower and out of its opposite side as shown in FIG. 1. This auxiliary trolley carries near one end four vertical sheaves 27, 28 and 29. The rope 13 that supports the bucket extends from the main trolley 3' back around sheave 27, while the bucket-closing rope 21 extends around sheave 28. From the anchor drums in the trolley the two ropes extend back around the two end sheaves 29 on the auxiliary trolley. All four lengths of these ropes then extend forward from the auxiliary trolley and up around another set of four sheaves 30 ro-.

tatably mounted on the tower. From this last set of sheaves the two ropes extend up to their respective supply reels, while their opposite ends extend in to the power drums on the tower. It will be seen that if the auxiliary trolley is moved toward the outer end of its track 26, the ropes will pull the main trolley along with it toward the tower.

In order to move the two trolleys in unison in both directions, the opposite ends of a wire rope 32 are connected to the outer end of the main trolley 3, from which the two lengths of the rope extend out and up around a pair of sheaves 33 journalled in the outer end of the boom. From these sheaves the lines extend back above the boom and tower and are wrapped a few times around an electrically driven drum 34 rotatably mounted on a pedestal 35 extending above the tower. From this drum the lines continue back'and down to a pair of sheaves 36 supported by a projection 37 from the tower, and then the lines extend back into the tower and around a pair of sheaves 38 carried by the adjacent end of the auxiliary trolley 25. From these sheaves the lines extend out along track 26 again and around a horizontal take-up sheave 39 that is supported from the outer end of the track. I

When the trolley drum 34 is rotatedin one direction,

4 the lines that are wrapped around it will pull trolley 3 toward the outer end of boom 1 and at the same time pay out the lines extending from the drum back to sheaves 36 so thatthe auxiliary trolley can be pulled by ropes l3 and 21 in the same direction as the main trol ley. When the trolley drum is reversed, the same lines 32 will pull the auxiliary trolley toward the outer end of its track while paying out, the lines extending forward to sheaves 33. During travel of the trolleys in either direction, the lines extending along the boom between the two trolleys are maintained under tension.

As this crane is used, the active portions of the two wire ropes l3 and 21; that is, the portions or lengths extending downwardly from the trolley anchor drums and around the bucket sheaves and then back up over the trolley sheaves and to the power drums, become worn so that eventually, for safetys sake, they must be replaced. With this invention the replacement is a simple matter. The ends of the ropes attached to the power drums are unclamped from those drums, the clamps l8 and 23 that hold the ropes near the supply reels are released and the locking pins that hold the anchor drums from rotating are pulled. Then the power drums l1 and 12 are operated to wind the ropes on them and to simultaneously unwind the released end portions of the ropes from those drums. This driving of the power drums causes the ropes to rotate the unlocked anchor drums and to pull new or unused rope from the supply reels. When lengths of the ropes that have not been worn during the operation of the crane reach the power drums, the ropes are clamped to those drums again but the worn lengths of ropes, which have now been wound off the power drums, are cut off and discarded. The anchor drums then are again locked against rotation and the lines hanging from the supply reels are again clamped to the tower. The crane is now ready for operation again. It will be seen that the only manual effort required is for unclamping the ropes and releasing the anchor drums and then reclamping the ropes and locking those drums. No restringing of the ropes is required because the unused lengths of the ropes follow the used lengths around the sheaves to the power drums. This manner of renewing the ropes therefore can be accomplished very quickly and easily.

Although sheaves 7, 8, 14 and have been referred to herein in the singular because that is the way they are shown in the drawings for convenience, it is to be understood that without departing from the invention each of these sheaves may actually be composed of two or more sheaves disposed side by side, with the wire ropes extending back and forth between the vertically spaced sheaves to obtain the conventional mechanical advantage.

According to the provisions of the patent statutes, 1 have explained the principle of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. A crane comprising a tower, a boom supported by the tower and extending substantially horizontally away from it, a main trolley supported by the boom, an auxiliary trolley at the inner end of the boom, a track for the auxiliary trolley extending away from the side of the tower opposite the boom, a pair of sheaves carried by the auxiliary trolley, a vertical sheave and a drum rotatably supported by the main trolley, a load carrier below the main trolley provided with a vertical sheave, a supply reel and a power drum rotatably supported by the tower, a line wound on the supply reel and extending therefrom around one of said auxiliary trolley sheaves and out to the trolley drum and completely around it and then down around the load carrier sheave and up and over the main trolley sheave and back around the other auxiliary trolley sheave and finally to the power drum, releasable means at the main trolley nonnally preventing said line from rotating the trolley drum, releasable means normally holding said line against unreeling from said supply reel, means for driving the power drum to wind the line on it to lift said load carrier, means for pulling the auxiliary trolley toward the outer end of said track to cause the length of said line between said other auxiliary trolley sheave and said trolley drum to pull the main trolley toward the tower, and means for pulling the main trolley toward the outer end of said boom to cause said length of line to pull the auxiliary trolley along with it, release of both of said releasable means permitting the power drum to withdraw line from the supply reel to replace with newline a used length of line between the reel and power drum.

2. A crane according to claim 1, including means detachably clamping one end of the line to the power drum and adapted to release that end before the power drum starts withdrawing new line from the supply reel, whereby during said withdrawing the used length of line can be removed from the power drum and discarded.

3. A crane according to claim 1, in which said load carrier is a clamshell bucket, the crane including a second vertical sheave and a second trolley drum rotatably supported by the main trolley, a second vertical sheave connected with the bucket, a second supply reel and a second driven power drum rotatably supported by the tower, a second pair of sheaves carried by the auxiliary trolley, a second line wound on the second supply reel and extending therefrom around one of said sheaves in the second pair of auxiliary trolley sheaves and out to the second anchor drum and around it and then down around the second load carrier sheave and up and over the second main trolley sheave and in around the other sheave in said second pair of sheaves and finally to the second power drum, releasable means at the main trolley normally preventing the second line from rotating the second trolley drum, and releasable means normally holding the second line against unreeling from the second supply reel, said second line serving to open and close the bucket.

4. A crane according to claim 1, in which said firstmentioned releasable means engages the trolley drum to lock it against rotation, and said line is wrapped around that drum enough times to prevent slipping on it when the line is pulled while the trolley drum is locked. 

1. A crane comprising a tower, a boom supported by the tower and extending substantially horizontally away from it, a main trolley supported by the boom, an auxiliary trolley at the inner end of the boom, a track for the auxiliary trolley extending away from the side of the tower opposite the boom, a pair of sheaves carried by the auxiliary trolley, a vertical sheave and a drum rotatably supported by the main trolley, a load carrier below the main trolley provided with a vertical sheave, a supply reel and a power drum rotatably supported by the tower, a line wound on the supply reel and extending therefrom around one of said auxiliary trolley sheaves and out to the trolley drum and completely around it and then down around the load carrier sheave and up and over the main trolley sheave and back around the other auxiliary trolley sheave and finally to the power drum, releasable means at the main trolley normally preventing said line from rotating the trolley drum, releasable means normally holding said line against unreeling from said supply reel, means for driving the power drum to wind the line on it to lift said load carrier, means for pulling the auxiliary trolley toward the outer end of said track to cause the length of said line between said other auxiliary trolley sheave and said trolley drum to pull the main trolley toward the tower, and means for pulling the main trolley toward the outer end of said boom to cause said length of line to pull the auxiliary trolley along with it, release of both of said releasable means permitting the power drum to withdraw line from the supply reel to replace with new line a used length of line between the reel and power drum.
 2. A crane according to claim 1, incLuding means detachably clamping one end of the line to the power drum and adapted to release that end before the power drum starts withdrawing new line from the supply reel, whereby during said withdrawing the used length of line can be removed from the power drum and discarded.
 3. A crane according to claim 1, in which said load carrier is a clamshell bucket, the crane including a second vertical sheave and a second trolley drum rotatably supported by the main trolley, a second vertical sheave connected with the bucket, a second supply reel and a second driven power drum rotatably supported by the tower, a second pair of sheaves carried by the auxiliary trolley, a second line wound on the second supply reel and extending therefrom around one of said sheaves in the second pair of auxiliary trolley sheaves and out to the second anchor drum and around it and then down around the second load carrier sheave and up and over the second main trolley sheave and in around the other sheave in said second pair of sheaves and finally to the second power drum, releasable means at the main trolley normally preventing the second line from rotating the second trolley drum, and releasable means normally holding the second line against unreeling from the second supply reel, said second line serving to open and close the bucket.
 4. A crane according to claim 1, in which said first-mentioned releasable means engages the trolley drum to lock it against rotation, and said line is wrapped around that drum enough times to prevent slipping on it when the line is pulled while the trolley drum is locked. 